1. Field of the Invention
The present invention relates to a pressure sensor and, more particularly, to an electrostatic capacity type pressure sensor to be packaged in an industrial device.
2. Description of the Related Art
As the electrostatic capacity type pressure sensor to be packaged in the industrial device of the prior art, there is a pressure sensor (as referred to Patent Publication 1), which comprises: a pressure receiving unit having a pressure receiving portion for sensing the pressure of a pressure fluid; a sensor unit having a sensor portion including stationary electrodes, and a moving electrode made movable in response to the pressure sensed by the pressure receiving unit and insulated and held between the stationary electrodes; and a signal processing unit having a reference portion and processing the electrostatic capacities of the sensor portion and the reference portion for outputting a desired signal.
[Patent Publication 1]
JP-A-7-286925 (pages 5 to 8, FIG. 1 and FIG. 2)
However, the pressure sensor of the prior art has a large number of parts and a complicated structure so that it has a large number of assembling steps and is difficult to reduce the size. Moreover, an accumulated error is so high as to make it difficult to retain a high assembling precision. This raises a problem that the dispersion of the operating characteristics is high.